hack/make: don't attempt to unmount non-existing daemon root-dir
hack/make: don't attempt to unmount non-existing daemon root-dir

Before:

    DONE 2 tests in 12.272s
    ---> Making bundle: .integration-daemon-stop (in bundles/test-integration)
    umount: bundles/test-integration/root: mountpoint not found

After:

    DONE 2 tests in 14.650s
    ---> Making bundle: .integration-daemon-stop (in bundles/test-integration)

Signed-off-by: Sebastiaan van Stijn <64b2b6d12bfe4baae7dad3d018f8cbf6b0e7a044@gone.nl>

kojiromike/docker,Ramzec/docker,Mokolea/docker,flavio/docker,gnailuy/docker,moul/docker,AkihiroSuda/docker,pradipd/moby,moul/docker,nalind/docker,AkihiroSuda/docker,kojiromike/docker,djs55/docker,vdemeester/docker,ibuildthecloud/docker,konstruktoid/docker-1,estesp/docker,estesp/docker,jameszhan/docker,Mokolea/docker,cpuguy83/docker,paralin/docker,yongtang/docker,gnailuy/docker,estesp/docker,mahak/docker,thaJeztah/docker,nalind/docker,Ramzec/docker,SvenDowideit/docker,nawawi/docker,flavio/docker,ibuildthecloud/docker,docker/docker,nalind/docker,djs55/docker,vdemeester/docker,konstruktoid/docker-1,justincormack/docker,jimjag/docker,paralin/docker,yosifkit/docker,yongtang/docker,jameszhan/docker,justincormack/docker,bearstech/moby,dims/docker,AkihiroSuda/docker,konstruktoid/docker-1,jthelin/docker,vdemeester/docker,moby/moby,moul/docker,ibuildthecloud/docker,moul/docker,SvenDowideit/docker,konstruktoid/docker-upstream,ibuildthecloud/docker,jimjag/docker,cpuguy83/docker,bearstech/moby,jthelin/docker,trebonian/docker,SvenDowideit/docker,mahak/docker,yosifkit/docker,AkihiroSuda/docker,konstruktoid/docker-upstream,gnailuy/docker,nawawi/docker,jimjag/docker,justincormack/docker,flavio/docker,jvanz/docker,pradipd/moby,nalind/docker,paralin/docker,Ramzec/docker,docker/docker,jvanz/docker,yosifkit/docker,trebonian/docker,konstruktoid/docker-upstream,gnailuy/docker,paralin/docker,trebonian/docker,kojiromike/docker,jimjag/docker,thaJeztah/docker,mahak/docker,dims/docker,Mokolea/docker,moby/moby,yongtang/docker,yosifkit/docker,bearstech/moby,nawawi/docker,cpuguy83/docker,dims/docker,djs55/docker,docker/docker,moby/moby,jameszhan/docker,jvanz/docker,flavio/docker,thaJeztah/docker,trebonian/docker,konstruktoid/docker-upstream,Mokolea/docker,moby/moby,thaJeztah/docker,ibuildthecloud/docker,mahak/docker,Ramzec/docker,pradipd/moby,cpuguy83/docker,bearstech/moby,nawawi/docker